Treason was the act of betraying one's country, organization, affiliation, or ally, usually to assist the enemy. One who committed this act was known as a traitor, and might be convicted as a criminal. Sometimes, a traitor was influenced by the enemy to commit such acts due to political or situational circumstances.

Curzon Dax was falsely accused of treason by the Klaestron for revealing the location of GeneralArdelon Tandro. In fact, Tandro himself was the traitor, and Dax was only guilty of committing adultery with Tandro's wife. (DS9: "Dax")